[2015-11-27 17:17:28,198] WARN JaudiotaggerParser - Error when parsing tags in /mnt/hdd1/Music/Discographies/DJ Andr$org.jaudiotagger.audio.exceptions.CannotReadException: No Reader associated with this extension:aac at org.jaudiotagger.audio.AudioFileIO.readFile(AudioFileIO.java:283) at org.jaudiotagger.audio.AudioFileIO.read(AudioFileIO.java:150) at org.madsonic.service.metadata.JaudiotaggerParser.getRawMetaData(JaudiotaggerParser.java:118) at org.madsonic.service.metadata.MetaDataParser.getMetaData(MetaDataParser.java:48) at org.madsonic.service.MediaFileService.createMediaFile(MediaFileService.java:735) at org.madsonic.service.MediaFileService.updateChildren(MediaFileService.java:584) at org.madsonic.service.MediaFileService.getChildrenOf(MediaFileService.java:307) at org.madsonic.service.MediaScannerService.scanFile(MediaScannerService.java:309) at org.madsonic.service.MediaScannerService.scanFile(MediaScannerService.java:313) at org.madsonic.service.MediaScannerService.scanFile(MediaScannerService.java:313) at org.madsonic.service.MediaScannerService.doScanLibrary(MediaScannerService.java:213) at org.madsonic.service.MediaScannerService.access$000(MediaScannerService.java:54) at org.madsonic.service.MediaScannerService$2.run(MediaScannerService.java:167)

I'm not sure if this is the answer you are looking for, but Plex will work on the Raspberry pi 2b if you follow this tutorial. I tried to get madsonic to work on my pi but I found the lack of support and unpredictableness of the software frustrating.